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You are almost to end! Go through the door and the last soldiers will be there, so take them out quick as there is only 4 or 5 of them. After defeating them, go left (if you go right you'll in up back in the lab). Then, go up the stairs and finally get the file and some ammo (not the last ammo). Go through the door to find green herb, handgun ammo, shotgun ammo, and mamum ammo. After you have the ammo, go down the stairs and watch the cutscene. Afterwards, take out your handgun and shoot his leg and he will fall. To do some extra damage you may knife him before you stab him. NOTE: (if you have a rocket launcher, when he falls to the ground hit his eye with the rocket launcher and Ada MIGHT give you the special rocket launcher it might take one more stab to the eye) after you stab him go near the bridge don't get on it and wait until he gets near the barrel and shoot it he'll fall to the ground stab him and go up to the second bridge don't get on it go up the platform press x to hold the crank wait for him to come and pull he will be hit by iron bars jump down and stab him then go back where the barrel was and shoot his eyeball on his leg NOTE:(repeat shooting the eyeball on his leg repeat this again and again and run around to avoid damage and go over iron bars at you so be ready to dodge) soon Ada will throw the special rocket launcher back up and shoot him to end the battle or if you kill him normal(shooting legs and etc.) you can keep the special rocket launcher and sell it for 30,000 gold after he's died enjoy a cutscene and then island will explode soon so you have to get out quick!